JP4146926B2 - Support spring member with wiring for optical and magnetic head and method for manufacturing the same - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a support spring member with wiring for optical and magnetic heads widely used in various electronic devices such as computer hard disks, floppy disks, CDs, MOs, and LDs, and a method of manufacturing the same. is there.
[0002]
[Prior art]
The conventional support spring member has a structure in which a support member made of an insulating material is attached on a base member, and a wiring member made of a conductive material is attached on the support member. For this reason, the wiring member is disposed on the support member in an exposed state, and is easily subjected to external force. Further, since the adhesion force between the wiring member and the support member depends on the adhesion force of the support member to the lower surface of the wiring member, the dimensional variation during processing and / or the insulating material forming the support member It had a defect such as insufficient adhesion due to variations during curing.
[0003]
In addition, since the conventional support spring member is exposed to etching several times after the wiring member is formed in a predetermined shape, the cross section of the wiring member has a shape with a drooping shoulder (for example, a trapezoidal shape). ) And the degree of sagging is uneven. For this reason, a wiring member having a required cross-sectional area is created by creating a wiring member with a relatively large cross-sectional area with respect to the dimensions at the time of design, which is not only uneconomical but also a wiring member. In order to avoid a short circuit between them, they must be formed with a sufficiently large separation interval, and high-density wiring cannot be performed.
[0004]
[Problems to be solved by the invention]
The present invention prevents the wiring member from being completely exposed on the support member, makes it difficult to receive an external force, and supports that can generate a large adhesive force between the wiring member and the support member. A spring member and a manufacturing method thereof are provided.
[0005]
The present invention further creates a wiring member having a cross-sectional area corresponding to the dimension at the time of design and a smaller separation interval by minimizing the possibility of deformation of the wiring member such as sagging during processing. Accordingly, it is an object of the present invention to provide a support spring member and a method of manufacturing the support spring member that can economically produce a support spring member having high-density wiring.
[0006]
[Means for Solving the Problems]
A support spring member according to the present invention includes a base member, a support member made of an insulating material attached on the base member, and a wiring member made of a conductive material embedded on the surface side of the support member. The above-mentioned problem is solved by being configured.
[0007]
Since the wiring member is embedded in the support member, no external force is applied to the wiring member. Further, since the adhesive force between the wiring member and the support member is joined to the support member in addition to the lower surface of the wiring member, it has a stronger adhesive force than the conventional one. On the other hand, since the support member made of an insulating material is interposed between the wiring members, the insulation between the wiring members can be improved, so that the wiring members can be arranged with a smaller separation interval. A smaller support spring member in which the wiring members are arranged at high density can be created. The base member can be made of stainless steel, the support member can be made of polyimide, and the wiring member can be made of copper.
[0008]
The support spring member according to the present invention can also cover at least a portion of the wiring member excluding the portion constituting the connection terminal with a protective member made of an insulating material. Since the wiring member is covered with the protective member, it is protected from oxidation, external force, and the like, and the wiring member can be prevented from being accidentally shorted or disconnected. The protective member can also be made of polyimide.
[0009]
Furthermore, the support spring member according to the present invention can also roughen the surface of the wiring member embedded in the support member, thereby increasing the binding force of the support member to the wiring member.
[0010]
The manufacturing method of the support spring member according to the present invention includes:
a) at least partially attaching a conductive wiring metal layer in a predetermined pattern to the surface of the barrier metal layer of the first laminated material in which the barrier metal layer is laminated on the support metal layer;
b) embedding a wiring metal layer attached to the surface of the barrier metal layer in the supporting insulating layer of the second laminated material in which the supporting insulating layer is laminated on the base metal layer;
c) removing the supporting metal layer of the first laminated material;
d) partially removing the barrier metal layer so that the barrier metal layer of the first laminated material has a predetermined shape surrounding the wiring metal layer;
e) partially removing the supporting insulating layer so that the supporting insulating layer of the second laminated material has a shape along the shape of the barrier metal layer of the first laminated material;
f) removing the barrier metal layer of the first laminated material left by partial removal;
g) forming a base metal layer into a predetermined shape as a support spring member.
[0011]
Since the wiring metal layer attached to the first laminated material is performed in a state where most of the subsequent steps are embedded in the supporting insulating layer of the second laminated material, the cross-sectional shape at the time of attaching to the first laminated material and The planar shape can be created in a state in which the shape is maintained by matching the required dimensional shape. In addition, since the wiring metal layer is not affected by etching or the like after being embedded in the support member, it is possible to avoid a dimensional change and to have a cross-sectional area corresponding to the dimension at the time of design. In addition, no external force is applied to the wiring member. In addition, since the support member is interposed between the wiring members, the insulation between them can be improved, so that the wiring members can be arranged with a smaller separation interval, and the wiring member pattern can be made smaller or more compact. The density can be increased.
[0012]
The manufacturing method of the supporting spring member according to the present invention may further include a step of attaching a protective insulating layer so as to at least partially cover the surface of the wiring metal layer from which the supporting metal layer and the barrier metal layer have been removed. Thus, the protective insulating layer can protect the wiring member from oxidation and external force, and prevent an inadvertent short circuit or disconnection. Furthermore, a metal material that can adhere the wiring metal layer on the intermediate metal layer plated on the barrier metal layer and securely bond the wiring metal layer to the barrier metal layer is used for the intermediate metal layer. You can also By interposing the intermediate metal layer, the wiring member can be reliably attached to the barrier metal layer.
[0013]
Furthermore, the method of manufacturing the support spring member according to the present invention can roughen at least the surface of the wiring metal layer attached to the barrier metal layer before embedding it in the support insulating layer. Thus, the bonding force between the wiring metal layer and the support insulating layer after being embedded in can be further increased.
[0014]
Furthermore, the manufacturing method of the supporting spring member according to the present invention uses a metal material that is the same or relatively easy to be etched as the conductive material forming the wiring metal layer for the supporting metal layer, and uses the supporting metal layer and the wiring metal layer. Metal material that can be etched by means different from the material to be formed is used for the barrier metal layer, and plastic material that can be etched by means different from the material to form the supporting metal layer, wiring metal layer and barrier metal layer is supported. A metal material that is used for the insulating layer and is not etched by each of the above-described etchings can also be used for the base metal layer, so that only the required layers can be processed in each step. A copper alloy layer is used for the supporting metal layer, a nickel layer plated on the supporting metal layer is used for the barrier metal layer, and a copper layer plated on the barrier metal layer is used for the wiring metal layer. A stainless steel layer may be used for the base metal layer, and a polyimide layer may be used for the supporting insulating layer and / or the protective insulating layer.
[0015]
DETAILED DESCRIPTION OF THE INVENTION
《Support spring member》
As shown in FIG. 1, the support spring member according to the embodiment of the present invention includes a base member 1 that constitutes the overall shape of a predetermined support spring member, and an insulating material attached on the base member 1. And a wiring member 3 made of a conductive material embedded in a predetermined pattern on the surface side of the support member 2.
[0016]
Any material can be applied to the base member 1 as long as it is a spring material. For example, a spring metal material such as a stainless steel, a copper alloy such as beryllium copper or phosphor bronze, or a nickel alloy can be used. Any material can be applied to the support member 2 as long as it can be molded while ensuring the required insulation. For example, a plastic material such as polyimide, epoxy, or acrylic can be used. Further, the wiring member 3 is for electrical connection, and any material can be applied as long as it has a good electrical conductivity. For example, a good conductor such as copper, copper alloy, nickel, gold or the like can be used. Metallic metal materials can be used. However, from the viewpoints of simplicity and cost in the processing steps described later, generally, the base member 1 is made of a stainless film, the support member 2 is formed of polyimide, and the wiring member 3 is formed of copper plating. Is done.
[0017]
In the support spring member of the present invention configured as described above, since the wiring member 3 is embedded in the support member 2, the influence from the outside on the wiring member 3 can be almost completely eliminated, and the support to the wiring member 3 is supported. Since the adhesive force of the member 2 is bonded to the support member 2 in addition to the lower surface of the wiring member 3, it is coupled with a very large force, and the wiring member 3 is peeled off due to variations in curing of the support member 2. It is possible to reliably prevent this. Furthermore, since the support member 2 made of an insulating material is interposed between the wiring members 3, the insulation between the wiring members 3 can be improved, whereby the wiring members 3 can be formed in a pattern with a smaller separation interval. The wiring member 3 can be disposed in a pattern that is smaller or more dense, and a smaller or more dense support spring member can be created.
[0018]
Here, the wiring member 3 embedded in the support member 2, which is one of the greatest features of the present invention, is disposed so as to be the same surface as the upper surface of the support member 2, but as shown in FIG. By forming the wiring member 3 into a shape that appropriately protrudes from the upper surface of the support member 2, the connection member can be more easily connected to the portion 3a (see FIG. 3) constituting the connection terminal of the wiring member 3. I can do it. Further, the protrusion of the wiring member 3 does not necessarily require that all the wiring members 3 protrude uniformly, and the same surface shape and the protruding shape can be mixed as required. Further, at least the exposed surface of the wiring member 3 is preferably provided with a gold plating 4 in order to prevent oxidation thereof.
[0019]
Further, as shown in FIG. 3, the wiring member 3 is preferably laminated with a protective member 5 made of an insulating material at least at a portion excluding the portion 3a constituting the connection terminal. The wiring member 3 can be reliably protected from force or oxidizing action. At this time, it can be easily understood that the gold plating 4 is applied only to the connection terminal 3a and the application range of the gold plating 4 can be reduced. The protective member 5 is formed of polyimide for the same reason as the support member 2.
[0020]
<< Method for Manufacturing Support Spring Member >>
As shown in FIG. 4, the manufacturing method of the supporting spring member according to the embodiment of the present invention includes a first laminated member creating step 10, a wiring metal layer attaching step 11, a wiring metal layer embedding step 12, a supporting metal layer removing step 13, It comprises a barrier metal layer partial removal step 14, a support insulating layer partial removal step 15, a barrier metal layer removal step 16, a protective insulating layer formation step 17, and a support spring member formation step 18. Hereinafter, each of these steps will be described. explain.
[0021]
A. First laminated member creating step (10)
A copper or copper alloy film having a thickness of about 0.15 mm is used as the supporting metal layer 20, and after pretreatment of the surface, electro nickel plating is performed on one surface of the supporting metal layer 20, so that a thickness of about 2 μm is obtained. A first laminated material is formed by laminating a barrier metal layer 21 of a nickel layer. As the first laminated material, a commercially available base material of a copper alloy-nickel laminated body can be purchased and used. Therefore, in the present invention, the step of creating the first laminated material is not necessarily an essential step. However, this first laminated material is shown in FIG. 5 in order to ensure the bond between the barrier metal layer 21 and the wiring metal layer 22 in the process of attaching the wiring metal layer 22 to the subsequent barrier metal layer 21. Thus, it is preferable to provide the intermediate metal layer 23 by electroplating the barrier metal layer 21 with the same metal material as the wiring metal layer 22.
[0022]
B. Wiring metal layer adhesion process (11)
After the surface of the barrier metal layer 21 or the intermediate metal layer 23 is pretreated, as shown in FIG. 6, a photoresist or a dry film is laminated, and then the photoresist is passed through a light shielding mask having a predetermined pattern. A resist pattern P is created by exposing and developing the substrate, and after pre-plating treatment, electrolytic copper plating is performed to form the wiring metal layer 22 in the resist pattern P. Preferably, the wiring metal layer 22 formed in the resist pattern is more securely bonded to the support insulating layer 24 after being embedded in the support insulating layer 24 in the subsequent wiring metal layer embedding step 12. Further, the exposed surface is roughened. This roughening is carried out so as to form an unevenness of 1 to 2 μm by spray etching. This roughening may be performed in a state where the wiring metal layer 22 is formed in the resist pattern. However, in order to secure a stronger bonding force with the support insulating layer 24, as shown in FIG. It is preferable that the side surfaces of the wiring metal layer 22 are also roughened by removing the resist pattern.
[0023]
C. Wiring metal layer burying process (12)
As the second laminated material, a laminated body in which a support insulating layer 24 made of polyimide is attached to a base metal layer 25 made of a stainless film is used. The wiring metal layer 22 is embedded in the supporting insulating layer 24 by applying a solvent such as N-methylpyrrolidone to the supporting insulating layer 24 to make it deformable, and the wiring metal layer 22 and the supporting insulating layer 24 are brought into contact with each other. After that, the wiring metal layer 22 is pressed into the support insulating layer 24 by pressing each other, and the solvent is removed by drying. However, preferably, as shown in FIG. 8, the wiring metal layer 22 is covered with a polyamic acid film 26 coated with a solvent, and then the second laminated layer is formed so that the support insulating layer 24 is in contact with the polyamic acid film 26. After the materials are laminated, the polyamic acid film 26 and the support insulating layer 24 are integrated by thermosetting the polyamic acid film 26, whereby the wiring metal layer 22 is embedded in the support insulating layer 24. According to this method, since the polyamic acid film 26 that changes to polyimide by thermosetting can completely encapsulate the wiring metal layer 22, it is between the wiring metal layer 22 and the support insulating layer 24 after being embedded. A gap or the like can be reliably avoided.
[0024]
D. Supporting metal layer removal step (13)
Etching is performed on the support metal layer 20 of the first laminated material, and only the support metal layer 20 is selectively removed as shown in FIG. When this etching is performed by photochemical etching, the supporting metal layer 20 and the wiring metal layer 22 are formed of the same or similar material, but the barrier metal layer 21 is disposed on the wiring metal layer 22, so that the wiring The metal layer 22 is masked by the barrier metal layer 21, so that the etching does not inadvertently reach the wiring metal layer 22, and in the case of laser or plasma etching, the barrier metal layer 21 serves as a removal interface, and etching is performed. Note that does not inadvertently reach the wiring metal layer 22.
[0025]
E. Barrier metal layer partial removal step (14)
Etching is performed on the barrier metal layer 21 of the first laminated material, and the barrier metal layer 21 is partially removed so as to have a predetermined shape surrounding the wiring metal layer 22 as shown in FIG. This step is performed by etching the intermediate metal layer 23 after etching the barrier metal layer 21 when the wiring metal layer 22 is attached to the barrier metal layer 21 via the intermediate metal layer 23.
[0026]
F. Support insulating layer partial removal step (15)
The exposed portion of the support insulating layer 24 not covered with the barrier metal layer 21 is removed by a suitable removing means, and the support insulating layer 24 formed in a predetermined shape surrounding the wiring metal layer 22 as shown in FIG. Create When the supporting insulating layer 24 is polyimide, this removing means is generally etched using hydrazine. However, after removing most of the exposed portion of the supporting insulating layer 24 by laser etching, etching using plasma is performed. It is preferable to completely remove the strain by heat, so that it is possible to avoid the occurrence of thermal distortion in the remaining necessary portion. At this time, the barrier metal layer 21 functions as a masking of the support insulating layer 24 against laser and plasma etching, and at the same time, the wiring metal layer 22 can be prevented from being processed.
[0027]
G. Barrier metal layer removal step (16)
The barrier metal layer 21 adhering to the partially left supporting insulating layer 24 is removed by an appropriate removing means, and the supporting insulating layer 24 is formed as a land on the base metal layer 25 as shown in FIG. Then, the support insulating layer 24 is formed into a shape in which the wiring metal layer 22 is embedded. This removing means is performed by selectively etching the metal material forming the barrier metal layer 21 by forming the barrier metal layer 21 and the wiring metal layer 22 from different metal materials. When the wiring metal layer 22 is attached to the barrier metal layer 21 via the intermediate metal layer 23, the barrier metal layer 21 is selectively etched after the barrier metal layer 21 is selectively etched, as in the case of the barrier metal layer partial removal step 5. It is desirable to gently etch the intermediate metal layer 23 so that even the layer 22 is not removed.
[0028]
H. Protective insulating layer forming step (17)
This step is performed in order with compatibility with a gold plating protection process, which will be described later, and can be selectively performed as necessary. A polyamic acid film 26 coated with a solvent is laminated on the wiring metal layer 22 from which the barrier metal layer 21 has been removed and the supporting insulating layer 24, and unnecessary portions are removed by etching using a photoresist, and then the polyamic acid film 26 is formed. The protective insulating layer 27 is formed by thermosetting. As a result, as shown in FIG. 13, the wiring metal layer 22 is covered with the protective insulating layer 27 made of an insulating material at least a portion excluding the portion 22 b constituting the connection terminal, and reliably from various influences from the outside. Protected. Here, it will be easily understood by those skilled in the art that the protective insulating layer 27 can be formed by laminating a photosensitive polyimide instead of the polyamic acid film, and directly exposing and developing the photosensitive polyimide.
[0029]
The connection terminal portion 22b of the wiring metal layer 22 is preferably subjected to conventional gold plating in order to prevent oxidation of the portion. At this time, since the portion excluding the connection terminal portion 22b is covered with the protective insulating layer 27, only a necessary portion can be plated with gold without using a light shielding means such as a mask, which contributes to cost reduction. can do.
[0030]
I. Support spring member forming step (18)
The base metal layer 25 including the support insulating layer 24 in which the wiring metal layer 22 is embedded is formed in the shape of a predetermined support spring member by processing means such as breath processing or etching.
[0031]
In the description of each step described above, the description regarding the pre-processing and / or post-processing associated with each processing is not made, but it will be easily understood by those skilled in the art that the pre-processing and / or post-processing is performed by conventional means. Like.
[0032]
Moreover, although the above-mentioned method was produced so that the wiring member 3 might become the same surface as the upper surface of the supporting member 2 as illustrated in FIG. 1 or FIG. 3, as illustrated in FIG. 2 and FIG. The required wiring member 3 can be formed into a shape that appropriately protrudes from the upper surface of the support member 2. In this case, there is a method of using a spacer Ru is projected wiring member 3, and the method of the support member 2 is removed using a laser or plasma.
[0033]
In the former method, in the wiring metal layer adhesion step 11, a photoresist having a thickness corresponding to the height at which the wiring member 3 protrudes from the upper surface of the support member 2, and a required thickness of the wiring member 3 together with this photoresist. A resist pattern is formed by laminating another photoresist for forming a thickness necessary for plating a thickness on the barrier metal layer 21 or the intermediate metal layer 23, and then exposing, developing, and plating as described above. After the wiring metal layer 22 is formed therein, only the latter photoresist is removed, leaving the former photoresist as it is. As a result, the remaining photoresist is interposed between the barrier metal layer 21 or the intermediate metal layer 23 and the support insulating layer 24 in the wiring metal layer embedding step 12, and in the subsequent barrier metal layer removing step 16. By removing, the wiring member 3 protruding from the upper surface of the support member 2 can be created.
[0034]
On the other hand, in the case of the latter method, a predetermined portion of the support insulating layer 24 is partially removed by using photochemical etching, laser and / or plasma etching at an appropriate time after the barrier metal layer removing step 16. By reducing the height, the wiring member 3 protruding from the upper surface of the support member 2 can be created. Here, in the case of the former method, all the wiring members 3 are formed in a shape protruding uniformly, whereas in the case of the latter method, the wiring member 3 can be formed in a shape protruding. Have advantages.
[Brief description of the drawings]
FIG. 1 is a cross-sectional view schematically showing a support spring member according to an embodiment of the present invention.
FIG. 2 is a view showing a modification of the support spring member shown in FIG.
FIG. 3 is a view showing another modified example of the support spring member shown in FIG. 1;
FIG. 4 is a block diagram illustrating a method of manufacturing a support spring member according to an embodiment of the present invention.
5 is a schematic cross-sectional view for explaining a first laminated member creating step of FIG. 4. FIG.
6 is a schematic cross-sectional view for explaining a wiring metal layer attaching step of FIG. 4;
7 is a schematic cross-sectional view for explaining a wiring metal layer burying step of FIG. 4;
8 is a schematic cross-sectional view showing the shape of a support spring member in the step of FIG.
9 is a schematic cross-sectional view for explaining the supporting metal layer removing step of FIG. 4. FIG.
10 is a schematic cross-sectional view for explaining the barrier metal layer partial removal step of FIG. 4;
11 is a schematic cross-sectional view for explaining the supporting insulating layer partial removing step of FIG. 4;
12 is a schematic cross-sectional view for explaining the barrier metal layer removing step of FIG. 4;
13 is a schematic cross-sectional view for explaining the protective insulating layer forming step of FIG. 4;
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 1 Base member 2 Support member 3 Wiring member 3a Connection terminal component part 4 Gold plating 5 Protection member 10 1st laminated member preparation process 11 Wiring metal layer adhesion process 12 Wiring metal layer embedding process 13 Support metal layer removal process 14 Barrier metal layer Partial removal process 15 Support insulation layer partial removal process 16 Barrier metal layer removal process 17 Protective insulation layer formation process 18 Support spring member formation process 20 Support metal layer 21 Barrier metal layer 22 Wiring metal layer 23 Intermediate metal layer 24 Support insulation layer 25 Base metal layer 26 Polyamic acid film 27 Protective insulating layer

Claims (8)

A base member;
A support member made of an insulating material attached on the base member;
A supporting spring member with wiring for optical and magnetic heads, comprising a wiring member made of a conductive material partially embedded in the thickness direction from the upper surface of the supporting member.   The support spring member according to claim 1, wherein at least a portion of the wiring member excluding a portion constituting the connection terminal is covered with a protective member made of an insulating material.   The support spring member according to claim 1 or 2, wherein the wiring member embedded in the support member has at least a roughened surface of a portion embedded in the support member. In the first laminated material in which the barrier metal layer is laminated on the support metal layer, a step of attaching a conductive wiring metal layer in a predetermined pattern to the surface of the barrier metal layer;
In the second laminated material in which the supporting insulating layer is laminated on the base metal layer, the step of at least partially embedding the wiring metal layer attached to the surface of the barrier metal layer in the thickness direction from the upper surface of the supporting insulating layer When,
Removing the supporting metal layer of the first laminated material;
Partially removing the barrier metal layer so that the barrier metal layer of the first laminated material has a predetermined shape surrounding the wiring metal layer;
Partially removing the supporting insulating layer so that the supporting insulating layer of the second laminated material has a shape along the shape of the barrier metal layer of the first laminated material;
Removing the barrier metal layer of the first laminated material left by the partial removal;
And a step of forming the base metal layer in a predetermined shape as a support spring member. A method of manufacturing a support spring member with wiring for optical and magnetic heads.   5. The method according to claim 4, further comprising a step of attaching a protective insulating layer so as to at least partially cover a surface of the wiring metal layer from which the barrier metal layer of the first laminated material is completely removed. Production method.   The wiring metal layer is deposited on an intermediate metal layer plated on the barrier metal layer, and the intermediate metal layer is interposed between the wiring metal layer and the barrier metal layer to ensure the coupling between the two. 6. The manufacturing method according to claim 4, wherein the manufacturing method is made of a metal material that can be applied.   7. The wiring metal layer attached to the barrier metal layer is roughened at least on the surface of the portion embedded in the support member before being embedded in the support insulating layer. Manufacturing method.   The supporting metal layer is made of a metal material that is the same as or relatively easy to etch the conductive material forming the wiring metal layer, and the barrier metal layer is a means for etching the material forming the supporting metal layer and the wiring metal layer, respectively. And the supporting insulating layer is made of a plastic material etched by means different from the material forming the supporting metal layer, the wiring metal layer and the barrier metal layer, respectively, and The said base metal layer consists of a metal material which is not etched by each said etching, The manufacturing method as described in any one of Claims 4-7 characterized by the above-mentioned.

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